only child of Emperor Leo IV and Irene . Constantine was crowned co-emperor by his father in 776, and succeeded as sole emperor at the age of nine under the regency of Irene in 780.
In 782 he was betrothed to Rotrude , a daughter of the Frankish King Charlemagne by his third wife Hildegard of Savoy . Irene herself broke off the engagement in 788. In 787 Constantine had signed the decrees of the Second Council of Nicaea , but he appears to have had Iconoclast sympathies. By then Constantine had turned 16 years old, but his mother did not relinquish executive authority to him.
After a conspiracy against Irene was suppressed in the spring of 790 she attempted to get official recognition as empress. This backfired and with military support Constantine finally came to actual power in 790, after the Armenians in the army rebelled against Irene. Nevertheless, she was allowed to keep the title of Empress, which was confirmed in 792.
The weakness of Constantine caused dissatisfaction among his supporters. He showed unheroic behaviour after the defeats at the hands of Kardam of Bulgaria in 791 and 792. A movement developed in favor of his uncle, the Caesar Nikephoros. Constantine had his uncle's eyes put out and the tongues of his father's four other brothers cut off. His former Armenian supporters revolted after he had blinded their general Alexios Mosele. He crushed this revolt with extreme cruelty in 793.
He then divorced his wife Maria, who had failed to provide him with a male heir, and married his mistress Theodote , an unpopular and possibly illegal act, although the Patriarch ignored it. By his actions Constantine had lost all support, both of the ruling orthodox and the iconclast opposition.
In 797 Constantine was captured and blinded by the supporters of his mother, who had organized a conspiracy. According to some historians, he died from his wounds, leaving Irene in sole control of the empire. Others, including Judith Herrin , assert that he survived the blinding and outlived his mother, dying in or shortly before 805. Pretenders to the throne claiming to be Constantine VI later appeared during the reign of Michael II .

790 AD
After some political unrest between Empress Irene and her son, Emperor Constantine VI, the Empress was forced to leave the imperial palace with Constantine VI becoming sole ruler of the Byzantine Empire (790-792 AD).
792 AD
The eager Emperor declared war on the Hunno-Bulgars in July and made his way with his forces to the frontier. This time, Kana Subigi Kardam met Emperor Constantine VI's forces in a full, pitched battle at the Fortress of Marcellae on July 20th. The Bulgars this day were victorious and slaughtered the Byzantines leaving their bodies upon the field with Emperor Constantine VI fleeing back towards Constantinople. Military equipment, loot, horses, and several Byzantine generals were captured at the end of the engagement. Kana Subigi Kardam was then met by an imperial entourage of diplomats sueing for peace. The peace was granted to the Byzantines on the condition of annual tribute to be paid to the Bulgars in gold every year. The Emperor then was forced to accept his mother back as co-ruler of the Byzantine Empire.
797 AD forcibly blinded by his mother and then kicked out of power, which won her no love amongst her subjects